A. Field of the Invention
The present invention relates generally to the field of telephone apparatus and more particularly to a prepay adapter circuit for converting central office telephone equipment from semi-postpay operation to full prepay operation.
B. Description of the Prior Art
Pay stations are generally available for full prepay operation with central office telephone equipment that includes control circuitry for operation of the pay station in a full prepay mode. One pay station of this general type is the Model 201 pay station manufactured by the Communication Equipment & Engineering Company of Melrose Park, Ill. 60160.
In many locations existing central office telephone equipment provides semi-postpay operation and is not compatible or capable of operation with full prepay, pay stations.
Thus, the need arises for circuitry to adapt or convert existing semi-postpay central offices for operation as full prepay central offices without extensive modifications of the existing central office telephone equipment and without the entire replacement of the central office equipment.